Bi-fuel engine with increased power

ABSTRACT

A conventional gasoline engine is retrofitted and calibrated to operate as a bi-fuel engine using Hydrogen as the second fuel. When operated with Hydrogen, which typically leads to a reduction of engine output power, the engine is preferably operated in a charged mode and in a lean mode with the engine throttle kept in a wide open position during charged and lean mode operation resulting in a more efficient engine with a reduction of engine output power loss.

This application is a continuation of application Ser. No. 14/556,776now U.S. Pat. No. 10,738,718 entitled “Bi-Fuel Engine With IncreasedPower,” filed on Dec. 1, 2014, which is a continuation of applicationSer. No. 12/795,440, now U.S. Pat. No. 8,931,463, entitled “Bi-FuelEngine With Increased Power” filed on Jun. 7, 2010 concurrently withcommonly owned and related application Ser. No. 12/795,410 entitled“Bi-Fuel Engine With Variable Air Fuel Ratio.”

BACKGROUND OF THE INVENTION Field of the Invention

The present invention generally relates to the design and control ofinternal combustion engines that can operate on two different fuels andthe relative power of the engines at the different fuels.

Description of the Related Art

Internal combustion engines operate on the principle of igniting amixture of air and gasoline (or other fuel) inside a cylinder to causecombustion within the cylinder where resulting released energy isconverted to mechanical energy through the use of a piston inside thecylinder driving a crankshaft. A fuel intake assembly, such as gasolinefuel injectors, is used to inject gasoline into cylinders or intakesystem of the engine. Internal combustion engines are typicallynaturally aspirated meaning that air is drawn from the environment atatmospheric pressure. As a result of the combustion of the air fuelmixture within a cylinder of the engine, different types of unwantedtoxic and pollutant gases are created in the cylinder and pass throughan exhaust system to a device commonly referred to as a catalyticconverter.

Typically, internal combustion engines (especially those used forautomobiles) use gasoline (or diesel) as a fuel which when burned in aninternal combustion engine generates exhaust gases some of which arepollutants and/or toxic. Other less polluting carbon based fuels or evennon-carbon based fuels can be used, but many of these fuels when mixedwith air don't have as nearly the same energy content (i.e., ‘mixturecalorific value’) for nearly the power output as when burning gasoline(i.e., gasoline mixed with air). It is desirable, however, to use someof these fuels because they can be used in what is referred to as a“lean mode” operation where virtually no toxic or polluting gases aregenerated from the combustion process. Operation in the lean mode refersto the air/fuel ratio with which the engine is being operated. Inparticular, the ratio of the amount of air and fuel in a combustionchamber of the engine will determine whether the engine is beingoperated in the lean mode or rich mode. For an ideal combustion theamount of air and fuel used for combustion in a chamber of an engine issuch that there is no residual oxygen or fuel remaining in the chamberafter combustion, the particular air fuel ratio is referred to as thestoichiometric air fuel ratio. The actual air fuel ratio, however, maynot be at stoichiometric at all times. A ratio of the actual air fuelratio to the stoichiometric air fuel ratio is referred to as λ. Thevariable λ is thus defined mathematically as:

$\begin{matrix}{\lambda = \frac{\left( \frac{{mass}\mspace{14mu}{of}\mspace{14mu}{air}}{{mass}\mspace{14mu}{of}\mspace{14mu}{fuel}} \right)_{actual}}{\left( \frac{{mass}\mspace{14mu}{of}\mspace{14mu}{air}}{{mass}\mspace{14mu}{of}\mspace{14mu}{fuel}} \right)_{stoichiometric}}} & (1)\end{matrix}$

When λ=1 the engine is operated at the stoichiometric air fuel ratiobecause the actual air fuel ratio is equal to the stoichiometric airfuel ratio as can be seen from equation (1) above. For value of λ<1, theengine is said to be in the rich mode. For λ>1, the engine is said to bein the lean mode. As can be seen from equation (1) above, in the leanmode more air is used in the combustion than in the stoichiometric mode.As a result operation in the lean mode although more desirable becausesuch a mode generates a lesser amount of harmful and/or pollutant gases,the loss of engine output power is exacerbated. Lean mode operation alsoresults in a relatively high efficient operation of the engine becauseof the relatively low fuel consumption. This relatively high efficiencyis often not realized because conventional gasoline engines typically donot run in lean mode.

Efficiency refers to fuel consumption for a defined engine output power.The more efficiently an engine is operating, the lower the fuelconsumption for a specific engine output power. Increasing theefficiency of an engine results in lowering the fuel consumption of theengine. In other words, an engine can generate a specific output powerby consuming a certain amount of fuel, but the same engine when runefficiently can generate the same amount of output power while consumingless fuel. One way to increase the efficiency of an internal combustionengine is to run the engine in lean mode.

BRIEF SUMMARY OF THE INVENTION

The method, device and system of the present invention provide an enginedesigned to operate with a first fuel with which it generates a certainengine output power and the engine is also designed to operate with asecond fuel with which it generates a lesser engine output power. Theengine is calibrated and retrofitted with a processor controlled airpump to significantly reduce the loss of engine output power when thesecond fuel is being used. When using the air pump during operation, theengine is said to be charged. The engine is also retrofitted with a fuelintake system for the second fuel and when using the second fuel, theengine is operated in a lean mode to improve efficiency while usingquality control. Calibration of the engine to run on Hydrogen (or anyother type of fuel) involves determining, calculating and setting theengine parameters to certain values to enable such operation.Retrofitting an engine refers to the modification and/or adjustment of anaturally aspirated engine, a turbocharged engine or a superchargedengine with the various components of the device of the presentinvention to operate in accordance with the method of the presentinvention.

The present invention comprises an air pump that can be coupled to theengine, a fuel intake system or assembly for the second fuel that can bemounted onto or within the engine and a processor that controls the fuelintake and air pump to selectively operate the engine using the secondfuel. The fuel intake assembly may comprise a fuel delivery system(e.g., fuel injectors for the first and second fuels) for both the firstand second fuels. The same processor can be used to operate the enginewith the first fuel. When using the second fuel, the processor of thepresent invention controls the air pump to operate the engine in acharged mode to increase engine output power and the processor operatesthe engine preferably in a lean mode to increase efficiency of theengine while using quality control. As a result, a naturally aspiratedengine will have a significantly reduced loss of output power whenoperated with the second fuel in a noncharged mode and said engine willoperate more efficiently using lean mode operation and quality control.Charging of the second gaseous fuel generates approximately the samepower output as the naturally aspirated first fuel. The charged moderefers to operation of the engine with the air pump which can be aturbocharger operated with and/or powered by exhaust gases of theengine. The pump can also be a supercharger (or any other pump) operatedby electrical or electronic control signals from the processor. As aresult, the engine can generate the same output power with the secondfuel as with the first fuel when operated in the charged mode.

In a first embodiment of the present invention, the device, system andmethod of the present invention retrofit and calibrate a naturallyaspirated engine operated with the first fuel (e.g., a gasoline engine)and also operated with a turbocharger when the second fuel is used. Theturbocharger is selected for proper operation with the second fuel toallow the engine to operate in a charged mode (turbocharger activated)and preferably in a lean mode using a second fuel such as Hydrogen gasor any other fuel. The operation of the engine with the second fuel innaturally aspirated operation results in a loss of output power of theengine. However, the operation of the engine in the charged mode withthe second fuel (e.g., a gaseous fuel), whereby exhaust gases resultingfrom the combustion of the second fuel are used to drive the turbocharger, significantly reduces the loss of output power of the engine.The output power of the engine is thus controlled by the amount of thesecond fuel being injected into the engine by using quality control.Quality control is a technique whereby the throttle of the engine ismaintained in a wide open position, i.e., a position whereby the flow ofair being pumped into the engine is not restricted by the throttleposition. A wide open position will vary for different types of enginesdepending on throttle design and engine speed. ‘Wide open’ thus refersto the opening of the throttle to a position so as not to restrict theair flow into the engine (the air being pumped into the engine by theturbocharger or supercharger or air pump). As a result, the loss ofoutput power of the engine using the second fuel is significantlyreduced but the engine operates more efficiently. For this embodiment,the turbocharger can be a Variable Turbine Geometry (VTG) turbocharger.

In a second embodiment of the present invention, the device, system andmethod of the present invention retrofit and calibrate a turbochargedengine or a supercharged engine (i.e., engines originally designed witha turbocharger or a supercharger) to allow the engine to operate withthe second fuel preferably in a lean mode.

For the second embodiment, in the case of a turbocharged engine, asecond turbocharger selected for proper operation with the second fuelis added. Such a turbocharger is activated during operation with thesecond fuel (e.g., Hydrogen) while the originally designed turbo chargeris deactivated or bypassed during such operation. Also, a processorcontrolled supercharger may be used to operate the engine in a chargedmode when using the second fuel.

For the second embodiment, in the case of a supercharged engine, thesupercharger can be operated (i.e., controlled electrically orelectronically) at an appropriate power capacity to pump the properamount of air into the engine when the second fuel (e.g., Hydrogen) isused by the engine. Also, a turbocharger can be added to the engine tooperate the engine in a charged mode using the exhaust gases resultingfrom the combustion of the second fuel. As a result, for the case of anadded second turbocharger or the use of a supercharger, the loss ofpower due to the use of the second fuel is significantly reduced. Aswith the first embodiment, quality control during lean mode operationare used when the second fuel is being used. That is, the throttle ofthe engine is kept in a wide open position (i.e., no restriction of airflow into the throttle) when using the second fuel in lean mode toimprove engine efficiency. The output power of the engine is thencontrolled by the amount of the second fuel being injected into theengine.

In a third embodiment of the present invention, the device, system andmethod retrofit and calibrate a turbocharged engine wherein theoriginally designed turbocharger is removed and is replaced with a newturbocharger designed to operate with the exhaust gases of either thefirst or the second fuel. The exhaust gases resulting from thecombustion of the first fuel have a certain first enthalpy or enthalpyrange. The exhaust gases resulting from the combustion of the secondfuel have a certain second enthalpy or enthalpy range. For thisembodiment and the other embodiments, combustion of the fuel isunderstood to mean the combustion of a fuel with the proper amount ofair. This new turbocharger is designed so that it can operate (i.e.,properly driven) with the exhaust gases resulting from the combustion ofthe first fuel or the combustion of the second fuel. One particularexample of such a turbocharger is a VTG turbocharger designed to operatefor a relatively wide temperature range of exhaust gases; this type ofVTG turbocharger will hereinafter be referred to as a Super VTGturbocharger. Such a Super VTG turbocharger, for example, can beoperated with the exhaust gases resulting from the combustion ofgasoline or the combustion of Hydrogen. This Super VTG turbocharger can,in many cases, be used to operate with either the first or the secondfuel. As with the other embodiments, this Super VTG turbochargersignificantly reduces the loss of output engine power when the engine isoperated with the second fuel preferably in a lean mode and usingquality control. In this embodiment, for a supercharged engine, asimilar turbocharger can be used or the supercharger can be controlledby the processor to properly operate the engine for the different typesof fuels.

In the case where the first fuel is gasoline and the second fuel isHydrogen, the engine can be selectively operated by a user as either agasoline engine or a Hydrogen gas engine. The terms Hydrogen andHydrogen gas will hereinafter be used interchangeably to indicate thevarious states of Hydrogen which can be used in this claimed invention.In this case, the device, system and method of the present inventioncomprise a processor, an air pump coupled to the engine and implementedas a turbocharger (or supercharger) selected for proper operation withthe second fuel, and a fuel intake assembly implemented with hydrogenfuel injectors and gasoline fuel injectors mounted onto the engine whereboth the Hydrogen fuel injectors and the turbocharger (or supercharger)are controlled by the processor to operate the engine using Hydrogengas. When using Hydrogen gas, which generates less power than gasoline,the engine is preferably operated in a charged mode (turbocharged orsupercharged) and in a lean mode using quality control. Consequently,the loss of engine output power resulting from operation with fuels,such as Hydrogen or other gaseous fuels compared to liquid fuels, suchas gasoline, can be significantly reduced by using the method, deviceand system of the present invention.

BRIEF DESCRIPTION OF THE DRAWINGS

FIG. 1 shows one embodiment of the device and system of the presentinvention;

FIG. 2 shows a flow chart of the method of the present invention;

DETAILED DESCRIPTION

The method, device and system of the present invention provide an enginedesigned to operate with a first fuel with which it generates a certainengine output power and the engine is also designed to operate with asecond fuel with which it generates a lesser engine output power. Theengine is calibrated and retrofitted with a processor controlled airpump to significantly reduce the loss of engine output power when thesecond fuel is being used. When using the air pump during operation, theengine is said to be charged. The engine is also retrofitted with a fuelintake system for the second fuel and when using the second fuel, theengine is operated in a lean mode to improve efficiency while usingquality control. Calibration of the engine to run on Hydrogen (or anyother type of fuel) involves determining, calculating and setting theengine parameters to certain values to enable such operation.Retrofitting an engine refers to the modification and/or adjustment of anaturally aspirated engine, a turbocharged engine or a superchargedengine with the various components of the device of the presentinvention to operate in accordance with the method of the presentinvention.

The present invention comprises an air pump that can be coupled to theengine, a fuel intake system or assembly for the second fuel that can bemounted onto or within the engine and a processor that controls the fuelintake and air pump to selectively operate the engine using the secondfuel. The fuel intake assembly may comprise a fuel delivery system(e.g., fuel injectors for the first and second fuels) for both the firstand second fuels. The same processor can be used to operate the enginewith the first fuel. When using the second fuel, the processor of thepresent invention controls the air pump to operate the engine in acharged mode to increase engine output power and the processor operatesthe engine preferably in a lean mode to increase efficiency of theengine while using quality control. As a result, a naturally aspiratedengine will have a significantly reduced loss of output power whenoperated with the second fuel in the charged mode and said engine willoperate more efficiently using lean mode operation and quality control.The charged mode refers to operation of the engine with the air pumpwhich can be a turbocharger operated with and/or powered by exhaustgases of the engine. The pump can also be a supercharger (or any otherpump) operated by electrical or electronic control signals from theprocessor. As a result, the engine can generate the same output powerwith the second fuel as with the first fuel when operated in the chargedmode.

In a first embodiment of the present invention, the device, system andmethod of the present invention retrofit and calibrate a naturallyaspirated engine operated with the first fuel (e.g., a gasoline engine)and also operated with a turbocharger when the second fuel is used. Theturbocharger is selected for proper operation with the second fuel toallow the engine to operate in a charged mode (turbocharger activated)and preferably in a lean mode using a second fuel such as Hydrogen gasor any other fuel whose exhaust gases have less enthalpy than theenthalpy of the exhaust gases of the first fuel. The operation of theengine with the second fuel in naturally aspirated operation results ina loss of output power of the engine. However, the operation of theengine in the charged mode with the second fuel (e.g., a gaseous fuel),whereby exhaust gases resulting from the combustion of the second fuelare used to drive the turbo charger, significantly reduces the loss ofoutput power of the engine. The output power of the engine is thuscontrolled by the amount of the second fuel being injected into theengine while in the charged mode using quality control. Quality controlis a technique whereby the throttle of the engine is maintained in awide open position, i.e., a position whereby the flow of air beingpumped into the engine is not restricted by the throttle position. Awide open position will vary for different types of engines depending onthrottle design and engine speed. ‘Wide open’ thus refers to the openingof the throttle to a position so as not to restrict the air flow intothe engine (the air being pumped into the engine by the turbocharger orsupercharger or air pump). As a result, the loss of output power of theengine using the second fuel is significantly reduced and the engineoperates more efficiently. For this embodiment, the turbocharger can bea Variable Turbine Geometry (VTG) turbocharger.

In a second embodiment of the present invention, the device, system andmethod of the present invention retrofit and calibrate a turbochargedengine or a supercharged engine (i.e., engines originally designed witha turbocharger or a supercharger) to allow the engine to operate withthe second fuel preferably in a lean mode.

For the second embodiment, in the case of a turbocharged engine, asecond turbocharger selected for proper operation with the second fuelis added. Such a turbocharger is activated during operation with thesecond fuel (e.g., Hydrogen) while the originally designed turbo chargeris deactivated or bypassed during such operation. Also, a processorcontrolled supercharger may be used to operate the engine in a chargedmode when using the second fuel.

For the second embodiment, in the case of a supercharged engine, thesupercharger can be operated (i.e., controlled electrically orelectronically) at an appropriate power capacity to pump the properamount of air into the engine when the second fuel (e.g., Hydrogen) isused by the engine. Also, a turbocharger can be added to the engine tooperate the engine in a charged mode using the exhaust gases resultingfrom the combustion of the second fuel. As a result, for the case of anadded second turbocharger or the use of a supercharger, the loss ofpower due to the use of the second fuel is significantly reduced. Aswith the first embodiment, quality control during lean mode operationare used when the second fuel is being used. That is, the throttle ofthe engine is kept in a wide open position (i.e., no restriction of airflow into the throttle) when using the second fuel in lean mode toimprove engine efficiency. The output power of the engine is thencontrolled by the amount of the second fuel being injected into theengine.

In a third embodiment of the present invention, the device, system andmethod retrofit and calibrate a turbocharged engine wherein theoriginally designed turbocharger is removed and is replaced with a newturbocharger designed to operate with the exhaust gases of either thefirst or the second fuel. The exhaust gases resulting from thecombustion of the first fuel have a certain first enthalpy or enthalpyrange. The exhaust gases resulting from the combustion of the secondfuel have a certain second enthalpy or enthalpy range. For thisembodiment and the other embodiments, combustion of the fuel isunderstood to mean the combustion of a fuel with the proper amount ofair. This new turbocharger is designed so that it can operate (i.e.,properly driven) with the exhaust gases resulting from the combustionthe first fuel or the combustion of the second fuel. One particularexample of such a turbocharger is a VTG turbocharger designed to operatefor a relatively wide temperature range of exhaust gases; this type ofVTG turbocharger will hereinafter be referred to as a Super VTGturbocharger. Such a Super VTG turbocharger, for example, can beoperated with the exhaust gases resulting from the combustion ofgasoline or the combustion of Hydrogen. This Super VTG turbocharger can,in many cases, be used to operate with either the first or the secondfuel. As with the other embodiments, this Super VTG turbochargersignificantly reduces the loss of output engine power when the engine isoperated with the second fuel preferably in a lean mode and usingquality control. In this embodiment, for a supercharged engine, asimilar turbocharger can be used or the supercharger can be controlledby the processor to properly operate the engine for the different typesof fuels.

In the case where the first fuel is gasoline and the second fuel isHydrogen, the engine can be selectively operated by a user as either agasoline engine or a Hydrogen gas engine. The terms Hydrogen andHydrogen gas will hereinafter be used interchangeably to indicate thevarious states of Hydrogen which can be used in this claimed invention.In this case, the device, system and method of the present inventioncomprise a processor, an air pump coupled to the engine and implementedas a turbocharger (or supercharger) selected for proper operation withthe second fuel, and a fuel intake assembly implemented with hydrogenfuel injectors and gasoline fuel injectors mounted onto the engine whereboth the Hydrogen fuel injectors and the turbocharger (or supercharger)are controlled by the processor to operate the engine using Hydrogengas. When using Hydrogen gas, which generates less power than gasoline,the engine is preferably operated in a charged mode (turbocharged orsupercharged) and in a lean mode using quality control. Consequently,the loss of engine output power resulting from operation with fuels,such as Hydrogen or other gaseous fuels compared to liquid fuels, suchas gasoline, can be significantly reduced by using the method, deviceand system of the present invention.

It should be noted that in cases where the mixture of air and the secondfuel has less mixture calorific value (i.e., less energy content) thanthe mixture of air and the first fuel, the enthalpy of the exhaust gasesof the second fuel is less than the enthalpy of the exhaust gases of thefirst fuel. The exhaust gases from the first fuel result from thecombustion of said first fuel within the engine. Similarly, the exhaustgases from the second fuel are a result of the combustion of the secondfuel within the engine.

It should also be noted that the device, system and method of thepresent invention apply to engines referred to as Otto cycle engineswhich include gasoline internal combustion engines as well as Dieselinternal combustion engines converted to operate with gasoline orcompressed natural gas (CNG). It is well known that Diesel engines canbe converted to Otto cycle engines such as (1) internal combustionengines that run on CNG or (2) internal combustion engines that run ongasoline.

It should further be noted that for the second embodiment in the case ofa supercharged engine and for the third embodiment, the device, systemand method of the present invention can operate with a mix fuel. Mixfuel operation refers to the injection of the first and second fuelsinto the chamber of the engine so that combustion occurs as a result ofigniting a mixture of the first fuel, the second fuel and air in theengine chamber. That is, the fuel used to operate these embodimentscomprises both the first fuel and the second fuel, i.e., a mix fuel. Themix fuel comprises a portion of the first fuel and a portion of thesecond fuel. The relative portions of the first and second fuels willdetermine the enthalpy of the exhaust gases resulting from thecombustion of the mix fuel.

Referring now to FIG. 1, there is shown the device and system of thepresent invention. Processor 102 has a plurality of control lines 104,180, 106, 108, 110, 112, 114 and 116 for controlling valve 140, wastegate 178, valves 136, 150, 152, throttle 130, gasoline fuel injectors126 and Hydrogen fuel injectors 128 respectively. The processor has Ninputs where N is an integer equal to 1 or greater. Processor 102 can bea microprocessor, a microcontroller, or a computer any of which can beprogrammed to control and operate the engine as described herein.Alternatively, a vehicle engine Electronic Control Unit (ECU) can beprogrammed to perform the tasks of processor 102 thus avoiding the useof a separate processor 102. The inputs are signals from various enginesensors, monitors and status indicators. For example, the inputs cancomprise various engine parameters such as engine pressure, enginespeed, engine temperature, boost pressure, vacuum pump operation,acceleration pedal position, throttle position, H2 sensor output, λsensor output, and air mass flow sensor output. Engine parameters arevariables which when analyzed reflect the status of an engine and itsoperation. The values of one or more engine parameters can be processed,manipulated and/or modified to control the operation of the engine.Calibration of the engine to operate with Hydrogen gas (or any otherfuel) involves determining, calculating and setting the various engineparameters to allow such operation. The input signals reach processor102 via any well known manner for carrying signals to a processor. Forexample, the signals may be part of a wireless communication system,optical signals, electrical signals and/or electronic signals. Processor102 indirectly controls the operation of the turbo charger throughcontrol of waste gate 178 and valves, 150 and 152. The turbo chargercomprises turbine 148 coupled to shaft 146 which drives compressor 144.Valves 136 and 140 are positioned within or along air intake conduits170 and 160 respectively to control air flow within such air intakeconduits both of which are coupled to throttle 130. Valves 150 and 152are positioned within or along exhaust pipes 162 and 158 respectively tocontrol exhaust gas flow within such exhaust pipes both of which arecoupled to catalytic converter 156 via exhaust pipe 154. The valves 150and 152 serve to route the exhaust gases through exhaust pipe 158 tobypass waste gate 178 and the turbocharger 144, 146, 148. Waste gate 178is positioned along or within exhaust pipe 163 to control exhaust gasesflowing through this exhaust pipe which serves as a turbocharger bypassroute for at least a portion of the exhaust gases routed to engage theturbocharger.

Engine 134 has intake manifold 132 on which processor controlledgasoline fuel injectors 126 and processor controlled Hydrogen gas fuelinjectors 128 are mounted. The fuel injectors for the second fuel and/orthe first fuel may also be positioned within chambers of the engine foran arrangement commonly referred to as direct injection. Gasoline fuelis fed to the gasoline fuel injectors 126 via fuel line 122 from fueltank 118. Hydrogen gas fuel is fed to the Hydrogen gas fuel injectors128 via fuel line 124 from fuel tank 120. Engine 134 further has exhaustmanifold 138 from which exhaust pipe 162 extends. During operation ofthe engine 134 exhaust gases escape through exhaust pipe 162 and areeither routed to engage turbine 148 of the turbocharger or are caused tobypass the turbocharger by routing them through exhaust pipe 158 tocatalytic converter 156 and emitted to the outside environment.Operation with gasoline as the first fuel resulting in a higher outputpower than Hydrogen is now discussed.

When using gasoline as the first fuel, the method, device and system ofthe present invention control the various valves to avoid operating theturbocharger. The engine is thus operated in the no charge mode. Inparticular, on the intake side of the engine 134, processor 102 controlsthrottle 130 and gasoline fuel injectors 126 to inject the proper amountof gasoline and draw the proper amount of air into the intake manifold132 based on the engine parameters in a well known manner. As engine 134is naturally aspirated, processor 102 opens valve 140 thus allowingfresh air to be drawn into throttle 130 by way of air intake conduit 160using paths 168 and 182 as shown. Processor 102 controls the position ofthrottle 130 to provide the proper proportions of air to mix withinjected gasoline within the chambers of engine 134. On the exhaust sideof the engine 134, exhaust gases emanating from pipe 162 of exhaustmanifold 138 are routed through exhaust pipe 158 taking path 166 asshown. The path taken by the exhaust gases is a result of processor 102opening valve 152 and closing valve 150 thus preventing the exhaustgases from engaging turbine 148. The exhaust gases bypass theturbocharger by flowing through exhaust pipe 158 onto exhaust pipe 154to catalytic converter 156 after which they are emitted to theenvironment. Operation of the engine using gasoline may be selectedthrough the use of a fuel selector switch (not shown) by the operatorwho may wish to switch operation to a second fuel such as Hydrogen. Fora naturally aspirated engine in the no charge mode, air is drawn intothe engine and no turbocharger or air pump is used. In the charged mode,the turbocharger is activated using the exhaust gases of the secondfuel. The charged mode operations are now described for the variousembodiments.

Still referring to FIG. 1, for the first embodiment, where the engine isnaturally aspirated, the turbine 148, shaft 146 and compressor 144comprise the turbocharger. In the charged mode, the turbocharger isactivated by the exhaust gases which are routed to engage turbine 148 ofthe turbocharger and continue via path 172 to catalytic converter 156.The routing is done by the processor closing valve 152 and opening valve150 allowing the exhaust gases to engage turbine 148 of theturbocharger. Turbine 148 then turns shaft 146 which operates compressor144 causing said compressor to pump fresh air into the throttle 130 viapaths 174 and 176. Valve 140 is also closed by processor 102. On its wayto throttle 130 the air is cooled by intercooler 142. Waste gate 178 isopened or closed by the processor to control the boost pressure of theengine. That is, part of the exhaust gases is caused to bypass theturbine via exhaust pipe 163 as shown by path 164.

For the second embodiment, turbine 148, shaft 146 and compressor 144constitute the second turbocharger. In the case where a supercharger isused, the second turbocharger shown in FIG. 1 is replaced with asupercharger (not shown), i.e., an electronically controlled air pump.For ease of illustration, the originally designed turbocharger is notshown, but is understood to be arranged in the same manner as the addedsecond turbocharger shown in FIG. 1. The second turbocharger isactivated in a similar manner as described in the first mode chargedoperation. That is, the second turbocharger is activated in a similarfashion as in the first embodiment using the exhaust gases of the secondfuel. In the case of a supercharged engine, the originally designedsupercharger is activated through control signals from processor 102.Alternatively, for a supercharged engine, a second turbocharger can beused instead of using the original supercharger to operate the engineusing the second fuel. When using the second fuel, the engine ispreferably operated in a lean mode using quality control.

For the third embodiment, the turbocharger shown may be a turbocharger(for example a Super VTG turbocharger) designed to operate for a definedrange of exhaust gas temperatures and/or enthalpies or enthalpy rangesand thus can be activated during operation with either the first orsecond fuel. This turbocharger is activated using the exhaust gases ofthe second fuel in a manner similar to what is described and shown inFIG. 1. When using the second fuel, the engine is preferably operated ina lean mode using quality control.

It should be noted that Hydrogen, can be used as a fuel by an internalcombustion engine with the proper mix of Hydrogen and air for what isreferred to as “lean” operation. Depending on the particular engine,lean mode operation with Hydrogen for various ranges of values of λresults in very little or no harmful exhaust gas emissions. The presentinvention is not limited to Hydrogen as the second fuel; othernon-carbon based fuels may be used in place of Hydrogen. A non-carbonbased fuel is matter that can be combusted in an internal combustionengine where none of the atomic or molecular components of the matter isCarbon.

An operator of the engine may be able to operate a fuel selector switch(not shown) to determine under which fuel the engine is to be operated.The fuel selector switch (not shown) may be coupled or connected toprocessor 102 as one of its inputs I1, . . . , IN. The fuel selectorswitch indicates to the processor under which fuel the engine is to beoperated.

When the fuel selector switch is set to the second fuel (e.g., Hydrogenoperation), the method, system and device of the present inventionoperate the engine 134 with processor 102 controlling the intake (i.e.,air intake and fuel intake) and exhaust sides of the engine usingquality control. The second fuel is mixed with air to operate the enginepreferably in lean mode. Processor 102 controls Hydrogen gas fuelinjectors 128 via control line 116 to inject Hydrogen gas into theengine thus controlling fuel intake of the engine. Processor 102 opensthrottle 130 and maintains throttle 130 in a wide open position(throttle 130 open so as not to restrict the air flow); this is referredto as quality control. When an increase in engine output power isrequired, the amount of fuel being injected is increased. Further,processor 102 activates the turbocharger 148, 146, 144 by closing valve152 and opening valve 150 allowing the exhaust gases to engage turbine148 causing shaft 146 to rotatably engage or drive compressor 144resulting in fresh air being pumped into air intake conduit 170. On theintake side of the engine processor 102 opens valve 136 and closes valve140 to route the pumped fresh air to path 176 to throttle 130 thuscontrolling the air intake of the engine. As the fresh air flows tothrottle 130 (maintained in a wide open position), it is cooled by anywell known cooling device 142 positioned along air intake conduit 170.Further, processor 102 controls waste gate 178 via control line 180 toallow some of the exhaust air flow to bypass the turbo charger throughexhaust pipe 163 via paths 164 and 172 to control the amount of exhaustgases that engage the turbocharger to modify (i.e., either increase ordecrease) the boost pressure of the engine and thus the output power ofthe engine.

The device of the present invention has been described in terms of agasoline engine vehicle retrofitted and calibrated to operate as abi-fuel engine using Hydrogen gas as the second fuel. Other fuels suchas Compressed Natural Gas (CNG) can also be used as the second fuel withthe device of the present invention and ethanol can also be used as thefirst fuel of the device of the present invention. An originallydesigned engine (needs no retrofitting) built to operate with a firstfuel of gasoline (or other liquid fuels such as Ethanol) and secondfuels such as Hydrogen or other gaseous fuels can also be used as partof the device of the present invention. Further, the engine whetherretrofitted or originally designed to operate with the claimedinvention, can be a naturally aspirated engine, a turbo charged engine,or a super charged engine.

It will be readily understood that FIG. 1 may also represent a system inwhich an internal combustion engine is calibrated and retrofitted tooperate as described with various modifications as may be considered byone skilled in the art to which this invention belongs. For example, thesystem of the present invention may be used to generate electricitywherein various parts of the system are not co-located, but are locatedat relatively large distances from each other. For example, theprocessor may be miles away from the engine and fuel delivery system andcontrols these components via a communication system. In general, whenvarious parts of a system are said to be not co-located, this refers toarrangement of these parts so that they cannot be combined into a devicethat is portable or is part of a portable system such as a vehicle.Various exhaust pipes (e.g., 158, 162, and 163) and air intake conduits(e.g., 160, 170) may have relatively much longer lengths and thus mayneed additional pumps to enable the air flows. Further, the controllines and the input lines of the processor 102 may be part of an overallcommunication system which may be implemented as an optical system, atwisted pair wire electrical system or a wireless communication system.

The method of the present invention is shown in FIG. 2 wherein theengine 134 operates on a first fuel of a certain power output or on asecond fuel where said second fuel generates a lesser power output thanthe first fuel. Engine 134 can be a retrofitted and calibrated naturallyaspirated engine or it can be an originally designed turbocharged orsupercharged engine. In step 202, the power is turned on. The processor102 and associated actuators (not shown) that may or may not be part ofthe valves, throttle, waste gate and turbo charger are activated.Processor 102 reads the state of the fuel selector switch (not shown inFIG. 1) that may be operated by an operator prior to starting theengine.

In step 204, the method of the present invention determines which fuelhas been selected by the operator of the engine. In particular,processor 102 reads the status of the fuel selector switch. In step 204,if the processor has determined that the second fuel has been selected,the method of the present invention moves to step 210. Because, thesecond fuel generates a lesser engine output power, the method of thepresent invention will operate the engine in charged mode meaning an airpump (e.g., a turbocharger or supercharger) is used to pump air into theengine at a pressure higher than atmospheric pressure using qualitycontrol. For a naturally aspirated engine retrofitted with aturbocharger or supercharger, processor 102 is programmed to operate theengine in charged mode (i.e., activating the turbocharger orsupercharger) when the second fuel is selected.

In step 210, for the first embodiment, processor 102 sets the valves tooperate the engine in charged mode as has been described supra andpreferably in a lean mode using quality control. In particular, in step212, processor 102 re-routes the exhaust gases to operate theturbocharger (148, 146, 144) waste gate 178 and throttle 130 to controlthe amount of air pumped into the engine 134 as has been describedsupra. In the charged mode, throttle 130 can be maintained in a wideopen position (i.e., using quality control). For a naturally aspiratedengine retrofitted with a supercharger, processor 102 controls andoperates the supercharger to pump the proper amount of air into theengine. For the second embodiment, the second turbocharger is activatedand is driven or operated using the exhaust gases of the second fuel ashas been described above. The originally designed turbocharger isdeactivated. Also, instead of adding a second turbocharger, a processorcontrolled supercharger can be added to operate the engine in thecharged mode, with lean operation using quality control when operatingwith the second fuel. In the case of a supercharged engine, thesupercharger is activated; and properly operated by control signals fromprocessor 102 for charged operation using quality control for the secondfuel. Alternatively, for a supercharged engine, a turbocharger can beadded to operate the engine in charged mode, lean operation usingquality control as has been described above. For the third embodiment,the turbocharger with a defined temperature range (e.g., a VTGturbocharger with a relatively wide temperature range, i.e., a SuperVTG) is activated using the exhaust gases of the second fuel asdescribed with respect to FIG. 1. Such a turbocharger having a definedtemperature range of operation can be designed to operate with theexhaust gases of the first or second fuels. Quality control is used tooperate the engine for all three embodiments when the second fuel isselected. Further, for all three embodiments, the engine is preferablyoperated in a lean mode when the second fuel is selected.

Returning to step 204, if the fuel selector switch indicates to theprocessor 102 that the first fuel has been selected, the method of thepresent invention moves to step 206. In step 206 for the firstembodiment, (i.e., naturally aspirated engine) the method of the presentinvention operates the engine 134 in the no charge mode as has beendescribed supra. For the first embodiment, processor 102 is programmedto operate the engine in a no charge mode when the first fuel isselected. In particular, processor 102 sets the valves and controls thefuel injectors to bypass the use of the turbo charger. In the firstembodiment, for a naturally aspirated engine using the first fuel,throttle 130 may be controlled as needed (variable opening of thethrottle) to control operation of the engine 134 and not necessarily bekept in a fixed open position. For the second and third embodiments(turbocharged or supercharged engines), processor 102 operates theengine as designed.

In step 208, for the first embodiment, processor 102 controls thethrottle and fuel injectors to operate the engine as a naturallyaspirated gasoline engine with the proper control of throttle 130 andgasoline fuel injectors 126 for the first fuel. In the secondembodiment, processor 102 controls the throttle and fuel injectors tooperate the engine with the use of the original turbocharger orsupercharger as designed. Similarly, in the third embodiment, theprocessor controls the throttle and fuel injectors and turbochargerhaving a defined temperature range of operation as designed. Such aturbocharger can be designed to operate with the exhaust gases of thefirst or second fuel.

The method of the present invention operates an engine using either thefirst fuel or the second fuel. As such the method of the presentinvention can alternate between modes of operation such as operating theengine using a second fuel preferably in lean mode and using qualitycontrol or operating the engine as designed using the first fuel. Themethod of the present invention can alternate between modes of operationas is desired by an operator of the engine.

The present invention has been described in the context of a bi-fuelengine operating on a first fuel (e.g., gasoline) or a second fuel. Aconventional naturally aspirated vehicle gasoline engine can beretrofitted and calibrated to burn Hydrogen gas using a turbocharger ora supercharger or some well known type of air pump. Calibration of theengine to run on Hydrogen (or any other type of second fuel) involvesdetermining, calculating and setting the engine parameters to certainvalues to enable such operation. Retrofitting an engine refers to themodification and/or adjustment of a naturally aspirated engine, aturbocharged engine or a supercharged engine with the various componentsof the device of the present invention to operate in accordance with themethod of the present invention.

One manner in which an engine can be retrofitted is to use componentsfrom a cross platform kit comprising various components such as ahousing, a processor stored in the housing, a processor controlled airpump (e.g., turbocharger, supercharger), a processor controlledthrottle, an electric accelerator pedal and a processor controlled fuelintake assembly (e.g., predrilled intake manifold and fuel injectors forthe primary and secondary fuels). That is, the device of the presentinvention is prepared or packaged as a cross platform kit. Thepredrilled holes of the intake manifold have the proper diameters forinstallation of first and second fuel injectors which are also part ofthe kit. For example, an engine being retrofitted to become a bi-fuelengine that operates with gasoline as the first fuel and Hydrogen as thesecond fuel may be fitted with a pre-drilled intake manifold where thepredrilled holes of the intake manifold are openings through which thefuel injectors can be mounted. Also, the first and second fuel injectorsmay be installed or positioned on or proximate the engine so that theyinject their respective fuels directly into the engine cylinder orchamber; this technique is called direct injection. The kit may furthercomprise an electric accelerator pedal that can be coupled to theprocessor 102 via control lines and input lines to the processor 102 toallow the processor to determine the pedal position at a particularinstant in time. The term ‘cross platform’ refers to the ability to usethe same or similar kit to retrofit different types of internalcombustion engines. For variations in engine size and design, certaincomponents of the kit may be modified, but the basic set of componentsof a cross platform kit remains virtually the same from engine toengine. For example, the intake manifold may be smaller or bigger or adifferent shape for different engines, but the basic component of anintake manifold is constant for all kits. Alternate versions of thecross platform kit may not have a processor; instead, software havinginstructions to operate the engine as per the method of the presentinvention can be downloaded onto the ECU of the engine beingretrofitted. The downloaded software can complement the existingsoftware in the ECU to properly operate the engine. The cross platformkit is thus a grouping of components which when properly installed on aconventional (naturally aspirated, turbocharged or supercharged) engineto retrofit the engine allows the engine to operate as a bi-fuel enginewhere at least one of the fuels can be a non-carbon based fuel (e.g.,Hydrogen).

It will be readily understood, however, that engines originally designedspecifically to operate in accordance with the method, device and systemof the present invention can also be used and thus the present inventionis not limited to retrofitted engines. That is, the present inventioncan be implemented with an engine originally designed and manufacturedto operate in accordance with the method, device and system of thepresent invention. It will also be readily understood that the method,device and system of the present invention are not limited to theparticular retrofitted conventional gasoline engine shown in FIG. 2; theparticular engine in FIG. 2 is used for ease of explanation. Whenoperating an internal combustion engine with Hydrogen, (i.e., Hydrogengas, H2) the device, method and system of the present invention allowfor more power at lower engine speed (i.e., more low end torque) andreduced nitrogen oxides emissions at lower engine speeds. The termsHydrogen and Hydrogen gas will hereinafter be used interchangeably toindicate the various states of Hydrogen which can be used in thisclaimed invention.

The device, system and method of the present invention have beendescribed in terms of various embodiments as described herein. It willbe readily understood that the embodiments disclosed herein do not atall limit the scope of the present invention. One of ordinary skill inthe art to which this invention belongs can, after having read thedisclosure may implement the device, system and method of the presentinvention using other implementations that are different from thosedisclosed herein but which are well within the scope of the claimedinvention.

What is claimed is:
 1. A device for operating an engine, the devicecomprising: a processor wherein said processor activates at least oneair pump coupled to the engine to operate the engine in a charged modeusing a first fuel, and wherein the processor deactivates the at leastone air pump to operate the engine in a charged and lean mode using asecond fuel.
 2. The device of claim 1, wherein the at least one air pumpis one of a turbocharger and a supercharger.
 3. The device of claim 2,wherein the turbocharger is a Variable Turbine Geometry (VTG)turbocharger.
 4. The device of claim 2, wherein the supercharger iselectrically or electronically controlled by the processor.
 5. Thedevice of claim 1, wherein the processor is one of a microprocessor, amicrocontroller, a computer, and an engine Electronic Control Unit. 6.The device of claim 1, wherein the engine is an Otto cycle engine. 7.The device of claim 1, wherein during the charged and lean modeoperation, the processor controls engine air intake using qualitycontrol.
 8. The device of claim 1, wherein the engine is a bi-fuelengine.
 9. The device of claim 1, wherein the engine is a naturallyaspirated engine.
 10. The device of claim 1, wherein the first fuel is acarbon based fuel.
 11. The device of claim 10, wherein the carbon basedfuel is one of gasoline, Compressed Natural Gas (CNG), Ethanol, andDiesel fuel.
 12. The device of claim 1, wherein the second fuel is anon-carbon based fuel.
 13. The device of claim 12 wherein the non-carbonbased fuel is Hydrogen.
 14. The device of claim 1, wherein the processorcontrols a fuel intake assembly having at least one fuel injector forthe first fuel and at least one fuel injector for the second fuelwherein said fuel intake assembly is mounted onto the engine.
 15. Thedevice of claim 14, wherein the first fuel is fed to the at least onefirst fuel injector via a first fuel line from a first fuel tank, andthe second fuel is fed to the at least one second fuel injector via asecond fuel line from a second fuel tank.
 16. The device of claim 14,wherein the at least one fuel injector for the first fuel is a carbonbased fuel injector and the at least one fuel injector for the secondfuel is a non-carbon based fuel injector.
 17. The device of claim 16,wherein the carbon based fuel injector is a gasoline fuel injector andthe non-carbon based fuel injector is a hydrogen fuel injector.
 18. Thedevice of claim 1, wherein the processor has N inputs for receivinginput signals where N is an integer equal to 1 or greater.
 19. Thedevice of claim 18, wherein the processor is configured to receive theinput signals from sensors, monitors or status indicators of the engine.20. The device of claim 19, wherein the input signals are engineparameters comprising at least one of engine pressure, engine speed,engine temperature, boost pressure, vacuum pump operation, accelerationpedal position, throttle position, Hydrogen sensor output, λ sensoroutput, and air mass flow sensor output.
 21. The device of claim 19,wherein the input signals are one of optical signals, electricalsignals, electronic signals, and wireless signals.
 22. The device ofclaim 21, wherein the wireless signals are signals from at least onewireless communication system.